sensing cold fire

[darryl]

Woke up this AM wondering how to sense when propane is burning in a catalytic burner device. The idea is to sense the heat of the flame to verify that it is burning, and to give a display for your eye to catch. In a sense it's a window that will glow brightly when your fuel is burning, but remain dim if no burning is detected. I guess it's a quartz plate- or a plate sandwich with a layer of special phosphor between- something like that. It would light up like neon, but only when a specific temperature has been reached. It becomes a sensor that you attach to the housing that contains the catalytic chamber. Even though you don't see the burning by eye, the chemistry of the sandwiched layer would respond, and give an indication by glowing at some interesting color. It would be a good sensor to have mounted on the side of your burner cannister- an indicator that would tell you that either your fuel is being consumed, or that it is being fed through unburned. Something you might want to know.

The burner cannister itself might be a camp heater, or it might be arranged as a cook top, but it would generally be powered by a 1 lb propane cylinder. What I'm looking for is the special phosphor material that can do the job, to use in making the sensor. Maybe it's not a phosphor- maybe it's a spray-on of certain ions or something. A reactive material in any case. A resonant ceramic matrix perhaps- I don't know. What is it?

[Tobias-B]

Sounds like a thermocouple, an amplifier, and a light bulb to me.

but I think electronically.

t

[J Tiers]

A couple links found quickly....

How hot is the area to be sensed? Most of the paint seems to be for temperatures considerably less than flame type temps.

https://www.thermometersite.com/technology

https://www.paintwithpearl.com/shop-custom-paint/temperature-changing-paint/

[Paul Alciatore]

Sounds like an electronic project to me also. Perhaps one of those no contact thermometers would be a good way.

But if you want something mechanical and that changes color when a specific temperature is reached, you could start with one of those thermometers that are made to stick in an object or liquid and that have a round face with a needle to indicate the temperature. Instead of the needle, you could attach a disk to the rotating shaft and color it so that the desired color would show through some holes or slits in a cover when the desired temperature is reached.

[SLK001]

...an indicator that would tell you that either your fuel is being consumed, or that it is being fed through unburned. Something you might want to know.

They are made to shut off if gas is on, but not lit. It's a small, fluid filled valve that the fluid expands when heated and keeps the valve open.

[Baz]

What about the visually impaired? How about a bimetallic strip that bends such that when at temperature it releases a ball bearing that drops down and strikes a bell 😃

[J Tiers]

What about the visually impaired? How about a bimetallic strip that bends such that when at temperature it releases a ball bearing that drops down and strikes a bell 😃

That's ADA non-compliant.... deaf people cannot hear it, and it's a safety device.....😜

[Jerrythepilot]

This is a machining forum. Sterling engine?

[boslab]

Thinking catalytic plus thermo sensitive
gauze heats colour changes it would be bugger all use for blind folk though
mark

[J Tiers]

There must be some way to load it up with so much electronic stuff that it barely works...... Make certain that it cannot run without grid electricity, that's a requirement these days for anything and everything..
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But I'd rather not.

What is this thing? Is it a particular device? Where is it used? Where and how it is used is important for determining the best sensing solution.

For some applications, the bimetal is a great idea, have it default to showing a red "not working" indication, and have it not push that up if the heat of it working is sensed.

[darryl]

My first use of the sensor would be for a water heater for camping. Sure I can put a pot of water on a camp stove, but this project is destined to be a stand-alone unit that doesn't interfere with cooking. It's probably going to stand on the ground, and I want to be able to just glance at it and see whether it's working or not.